1. Field of the Invention
The present application relates to a method of fabricating a liquid crystal display device, and more particularly, to a method of fabricating a liquid crystal display device having a liquid crystal panel, a printed circuit board and a tap carrier package.
2. Discussion of the Related Art
As information age progresses, flat panel display (FPD) devices having light weight, thin profile, and low power consumption have been substituted for cathode ray tube (CRT) devices. Liquid crystal display (LCD) devices, plasma display panel (PDP) devices, field emission display (FED) devices, and electroluminescent display (ELD) devices are examples of the FPD devices. Since the LCD devices have excellent characteristics of high resolution, high contrast ratio and displaying moving images, the LCD devices have been widely used in a notebook computer, a monitor and a television.
In general, an LCD device includes a driving circuit unit that generates a gate signal, a data signal and a control signal using an image signal from an external system and supplies a power, a liquid crystal panel that displays images using the gate signal, the data signal and the control signal, and a backlight unit that supplies a light to the liquid crystal panel.
For example, the driving circuit unit includes a printed circuit board (PCB), where circuits generating RGB data and control signals using the image signal and a clock signal of the external system are formed, and a tape carrier package (TCP), where circuits generating the gate signal and the data signal using the RGB data and the control signals are formed. The PCB is connected to the liquid crystal panel through the TCP. The liquid crystal panel includes a first substrate having a pixel electrode, a second substrate having a common electrode and a liquid crystal layer. The first and second substrates face and are spaced apart from each other and the liquid crystal layer is interposed between the first and second substrates. The transmittance of the liquid crystal layer is changed according to the electric field generated between the pixel electrode and the common electrode to display the images. The backlight unit is disposed under the liquid crystal panel as a light source of the LCD device.
The LCD device is completed by modularizing the driving circuit unit, the liquid crystal panel and the backlight unit with a top frame, a main frame and a bottom frame. The steps of attaching the driving circuit unit such as the PCB and the TCP to the liquid crystal panel and wrapping the driving circuit unit, the liquid crystal panel and the backlight unit with the top, main and bottom frames may be referred to as a module process.
FIG. 1 is a view showing a method of fabricating a liquid crystal display device according to the related art.
In FIG. 1, a liquid crystal panel is fabricated through a panel process line 100. In a module process line 200, a tape carrier package (TCP) and a printed circuit board (PCB) are attached to the liquid crystal panel, and the liquid crystal panel, the TCP, the PCB and a backlight unit are assembled using a top frame, a main frame and a bottom frame, thereby a liquid crystal display (LCD) device completed.
In a liquid crystal injection apparatus 110, a liquid crystal layer is formed between a first substrate having a gate line, a data line, a thin film transistor (TFT) and a pixel electrode and a second substrate having a color filter layer, a black matrix and a common electrode, thereby the liquid crystal panel completed. The completed liquid crystal panel in the liquid crystal injection apparatus 110 is transferred to an auto probe apparatus 120. Defects of the liquid crystal panel such as an electric shortage or an electric disconnection in the gate line and the data line are inspected in the auto probe apparatus 120.
The liquid crystal panel passing the inspection of defects in the auto probe apparatus 120 is transferred to a polarizing plate attachment apparatus 210 in the module process line 200. In the polarizing plate attachment apparatus 210, a polarizing plate is attached to each of outer surfaces of the first and second substrates. Next, the liquid crystal panel having the polarizing plate is transferred to a tape automated bonding (TAB) apparatus 220 and the TCP is attached to each of adjacent side portions of the liquid crystal panel in the TAB apparatus 220. Next, the liquid crystal panel having the TCP is transferred to a PCB bonding apparatus 230 and the TCP is bonded to the PCB in the PCB bonding apparatus 230. Next, the liquid crystal panel having the TCP and the PCB is transferred to a resin coating apparatus 240. In the resin coating apparatus 240, a resin is coated onto connection portions of the liquid crystal panel and the TCP and of the TCP and the PCB and then the resin is cured.
Next, the liquid crystal panel is transferred to a driving circuit unit inspection apparatus 250 and defects in the TCP and the PCB are inspected in the driving circuit unit inspection apparatus 250. Next, the liquid crystal panel passing the inspection of defects in the driving circuit unit inspection apparatus 250 is transferred to a frame assembling apparatus 260. In the frame assembling apparatus 260, the top, main and bottom frames wrap the liquid crystal panel, the TCP, the PCB and the backlight unit so that the LCD device can be completed.
The panel process line 100 where the liquid crystal panel is fabricated has a different degree of cleanliness from the module process line 200 where the TCP and the PCB are connected to the liquid crystal panel. Since particles definitely deteriorate fine patterns such as the gate line, the data line and the TFT, the panel process line 100 may have a relatively high degree of cleanliness. In addition, since the particles seldom deteriorate the electric connections between large-sized patterns such as pads of the liquid crystal panel, the TCP and the PCB, the module process line 200 may have a medium degree of cleanliness for reduction in maintenance cost. For example, the panel process line 100 may have a first degree of cleanliness of class 1000 and the module process line 200 may have a second degree of cleanliness within a range of class 1000 to class 10000. Here, the class (ea/feet3) may be defined by the number of particles having a diameter over 0.5 μm in one cubic feet. In addition, the first degree of cleanliness of class 1000 may be defined to be higher than the second degree of cleanliness within a range of class 1000 to class 10000.
All the steps performed in the module process line 200 do not require the second degree of cleanliness, and some steps may be performed without reduction in process yield even under a degree of cleanliness lower than the second degree of cleanliness. However, since the steps in the module process line 200 may hardly be divided, production cost and fabrication time increase due to excessive maintenance cost for some steps.